Fabrication of electronic circuit elements using liquid deposition techniques is of profound interest as such techniques provide potentially low-cost alternatives to conventional mainstream amorphous silicon technologies for electronic applications such as thin film transistors (TFTs), light-emitting diodes (LEDs), RFID tags, photovoltaics, and the like. However the deposition and/or patterning of functional electrodes, pixel pads, and conductive traces, lines and tracks, which meet the conductivity, processing, and cost requirements for practical applications have been a great challenge.
Solution-processable conductors are of great interest for use in such electronic applications. Silver nanoparticle-based inks represent a promising class of materials for printed electronics. However, most silver (and gold) nanoparticles often require large molecular weight stabilizers to ensure proper solubility and stability in solution. These large molecular weight stabilizers inevitably raise the annealing temperatures of the silver nanoparticles above 200° C. in order to burn off the stabilizers, which temperatures are incompatible with most low-cost plastic substrates such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) that the solution may be coated onto and can cause damage thereto.
Furthermore, current silver nanoparticle compositions may have adhesion issues with some substrates. Simply rubbing and/or contacting the surface of the printed silver features may thus inevitably damage the printed features from such silver nanoparticle compositions. Thus, the poor adhesion of the silver nanoparticle composition may limit its use in certain applications, such as, for example, printed antennas.